Respuesta :
?x+3=3(-x+7)
?x+3=-3x-21
?x = -3x-21-3
?x +3x = -24
(?+3) x = -24
the equation has no solutions if (?+3)=0
?+3=0
? = -3
?x+3=-3x-21
?x = -3x-21-3
?x +3x = -24
(?+3) x = -24
the equation has no solutions if (?+3)=0
?+3=0
? = -3